Skip to main content
PermitBase

Accessory Dwelling Unit (ADU) in Unincorporated Davis County, Utah

Required for construction of a secondary dwelling unit on a residential property in Unincorporated Davis County, including basement apartments, detached cottages, and garage conversions. ADU permits follow the standard Davis County Building Permit Fee Schedule (valuation-based).

Verified 2026-07-01 · Source

When you need this permit

  • Property must be in unincorporated Davis County and zoned to allow an ADU
  • Compliant with Davis County Land Use and Development Management Ordinance (Title 15)
  • Separate entrance from primary dwelling
  • Must meet all IRC requirements for a dwelling unit (egress, smoke/CO detectors, etc.)

Required documents

Check off what you have — your progress is saved on this device.

Not ready yet — 0 of 2 required documents checked.

This checker covers one permit. A full project usually triggers several — our paid checklist will assemble all of them, from $29 →

Fee schedule

Building Permit — Valuation-basedGrounded: ADU construction (new dwelling space) is new residential construction, so the standard valuation-based Davis County Building Permit Fee Schedule applies — confirmed against the current fee schedule PDF (§ 2.48.050, Ord. No. 4-2017, fetched and text-extracted 2026-07-01 from daviscountyutah.gov/docs/librariesprovider28/default-document-library/current-fee-schedule.pdf), which shows the $200.00 tier-one minimum and confirms no separate ADU-specific building-fee line exists — ADUs use the general valuation table plus the fee schedule's distinct 'Accessory Units: $200.00' construction bond line. Valuation = total cost of all work (structural, MEP, finishes, labor).
Per the Davis County Building Permit Fee Schedule (§ 2.48.050(A), Ord. No. 4-2017): minimum $200.00, scaling with project valuation
Plan ReviewDavis County Code § 2.48.050(A), Ord. No. 4-2017.
65% of the building permit fee, or actual cost, whichever is less
Construction Bond — Accessory Units (refundable on approved final inspection)Grounded verbatim in the current Davis County Fee Schedule PDF (§ 2.48.050, Ord. No. 4-2017, fetched and text-extracted 2026-07-01): Construction Bonds section lists 'Accessory Units: $200.00' distinctly from 'Remodel or Addition to Existing Construction: $500.00' and 'New Construction: $1,000.00'.
$200.00

Review timeline

Plan reviewTypical estimate — confirm current times with the Unincorporated Davis County building department
~14–30 business days

How long did your Accessory Dwelling Unit (ADU) permit actually take in Unincorporated Davis County?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

  1. 1

    Foundation

    Footings, forms, rebar — before concrete pour

  2. 2

    4-Way Rough (Framing, MEP)

    Framing, fire separation between units, egress windows, and MEP rough-ins before walls closed

  3. 3

    Insulation

    Insulation and vapor barrier before drywall

  4. 4

    Final

    All work complete, smoke/CO detectors installed, address posted, ready for occupancy

See the full Unincorporated Davis County inspection guide — scheduling & re-inspection fees →

Tips

  • The fee schedule separately identifies 'Accessory Units' with a $200 construction bond (refundable) — lower than the $1,000 new construction bond.
  • Utah HB 82 (2021) requires most Utah jurisdictions to allow internal ADUs by right — contact Davis County Planning & Zoning at (801) 451-3278 to confirm current ADU rules for unincorporated areas.
  • Basement apartments require egress windows in every bedroom (5.7 sq ft minimum net clear opening, sill no higher than 44 inches above the floor).
  • ADU impact fees may be reduced or waived under Utah law — confirm with the county.

Frequently asked questions

Unincorporated Davis County requires an accessory dwelling unit (adu) permit for: Property must be in unincorporated Davis County and zoned to allow an ADU; Compliant with Davis County Land Use and Development Management Ordinance (Title 15); Separate entrance from primary dwelling; Must meet all IRC requirements for a dwelling unit (egress, smoke/CO detectors, etc.). If your project isn't listed, confirm with Davis County Community & Economic Development — Planning & Zoning at (801) 451-3278 before starting work.

ADU permit fees are valuation-based per County Code § 2.48.050 (Ord. 4-2017), plus a 65% plan review fee and a $200 refundable accessory unit construction bond. Call (801) 451-3278 for a fee estimate for your specific project.

Plan review for an accessory dwelling unit (adu) permit in Unincorporated Davis County typically runs 14–30 business days. This is an estimate, not a published figure — confirm current review times with Davis County Community & Economic Development — Planning & Zoning at (801) 451-3278.

You'll need: Building Permit Application (iworq); Full Construction Drawings. Depending on your project, Unincorporated Davis County may also ask for: Zoning Verification. See the required-documents checklist on this page for details on each.

Unincorporated Davis County requires 4 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation, 4-Way Rough (Framing, MEP), Insulation, Final. Schedule each through Davis County Community & Economic Development — Planning & Zoning ((801) 451-3278).

Apply through Davis County Community & Economic Development — Planning & Zoning at 61 South Main Street, Suite 304, Farmington, UT 84025. Phone: (801) 451-3278, email: planning@daviscountyutah.gov. Office hours: Mon–Fri 8:00 AM – 5:00 PM. Official information: https://www.daviscountyutah.gov/ced/planning/building-permits.

Unincorporated Davis County, Utah has adopted: 2024 International Building Code (IBC) — Utah Code § 15A-2-103(1)(a); effective July 1, 2026 (replaces 2021 IBC); 2021 International Residential Code (IRC) — Utah Code § 15A-2-103(1)(b); remains in force after July 1, 2026; 2024 International Plumbing Code (IPC) — Utah Code § 15A-2-103(1)(d); effective July 1, 2026 (replaces 2021 IPC); 2024 International Mechanical Code (IMC) — Utah Code § 15A-2-103(1)(e); effective July 1, 2026 (replaces 2021 IMC); 2024 International Fuel Gas Code (IFGC) — Utah Code § 15A-2-103(1)(f); effective July 1, 2026 (replaces 2021 IFGC); 2023 National Electrical Code (NEC) — Utah Code § 15A-2-103(1)(g); statewide in force. NOTE: Davis County's own website does not list a specific NEC edition — the statewide 2023 NEC is the legally in-force edition.; 2024 International Energy Conservation Code (IECC) — Utah Code § 15A-2-103(1)(h); effective July 1, 2026 (replaces 2021 IECC); Utah residential energy provisions effectively follow 2015 IECC residential; 2024 International Existing Building Code (IEBC) — Utah Code § 15A-2-103(1)(i); effective July 1, 2026 (replaces 2021 IEBC); 2024 International Swimming Pool and Spa Code (ISPSC), residential provisions — Utah Code § 15A-2-103(1)(n); effective July 1, 2026; NOTE: Through June 30, 2026, the 2021 editions of IBC, IPC, IMC, IFGC, IECC, IEBC, and ISPSC are in force per Utah Code § 15A-2-103 (version effective through 6/30/2026). Local amendments apply — see the Unincorporated Davis County overview page for the full list.

Utah law (HB 82, 2021) requires most Utah jurisdictions to allow internal ADUs. Contact Davis County Planning & Zoning at (801) 451-3278 to confirm ADU eligibility for your specific parcel and zone.

Sources & verification

Verified against official sources. Last reviewed 2026-07-01.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Unincorporated Davis County building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

Other permits in Unincorporated Davis County

Residential Building PermitElectrical PermitPlumbing PermitMechanical / HVAC PermitRoofing PermitDeck PermitSwimming Pool PermitSolar Panel PermitBasement Finish PermitDemolition PermitCommercial Building PermitCommercial Tenant Improvement / Tenant Finish PermitFire Sprinkler and Fire Alarm System PermitEV Charger / EVSE PermitSign PermitChange of Use / Certificate of Occupancy

Accessory Dwelling Unit (ADU) in other cities

Bountiful, UtahDraper, UtahEagle Mountain, UtahKaysville, UtahLayton, UtahLehi, UtahLogan, UtahNorth Salt Lake, Utah

Compare accessory dwelling unit (adu) fees across Utah →

Look up this fee in a different city →

Embed this data card →

Related guides

ADU / In-Law Suite

Now live

Build your Unincorporated Davis County project checklist

Describe your project once and get every permit, document, and fee it triggers in Unincorporated Davis County — in one checklist. Sign up and pay once to generate it, or go unlimited with Pro.

Get started →